In these days, various types of clinical analyzers for automatically analyzing biological liquids such as blood, serum and urine are being in practical use. Analysis of biological liquids basically involves mixing of liquid samples with reagents to allow for chemical or immunochemical reactions for determining presence and amount or absence of specific substances contained in the samples. For example, viral loads may be automatically quantified based on mixing of serum samples with specific reagents, followed by cycling the serum-reagent mixtures obtained through predefined temperature profiles to perform the polymerase chain reaction (PCR).
Since there is a strong demand for offering a wide variety of analytical functions and with a view to improve effectiveness in sample processing, modern analyzers most often process samples in parallel and/or split each sample into a number of aliquots for simultaneous processing thereof deploying different analytical techniques. As a result, due to higher sample throughput and dependent on the number of analytical options offered, modern analyzers are subject to an elevated consumption of reagents which may be satisfied in either preloading the analyzer with an adequate number of reagent containers or performing frequent manual reagent container reloading operations. In the first case, while analyzers can be used in a comfortable stand-alone mode, a larger number of stored reagent containers require much storage space which increases the overall dimensions of the analyzer. In the latter case, while analyzers can be made small and compact, frequent reagent container reloading operations increase the workload on technicians in charge of operating the analyzer, most notably in the event of short time intervals in-between consecutive reloading operations. Moreover, as each reloading operation causes a delay for starting the next run, frequent reloading operations lower effectiveness in sample processing. Even worse, in case the technician fails to reload reagent containers in a timely manner, missing reagents typically cause an interrupt of ongoing runs which may constitute a need to discard the samples currently processed. Some samples, however, are unique in a sense that they can hardly or even not be re-supplied such as in certain forensic cases.
In view of an increasing tendency to install small and compact analyzers to be placed on a laboratory bench or any other suitable surface which enable parallel sample processing and offer a wide variety of analytical options, a convenient trade-off between the number of stored reagent containers and the frequency of manual reloading operations when operating the analyzer in daily routine has to be found. In other words, there is a strong need for preloading (storing) as many reagent containers as possible in an otherwise small and compact analyzer.
In order to keep a comparably large number of reagent containers in readiness for sample analyzing, modern clinical analyzers typically are being provided with supplemental storage space such as supplemental reagent container racks as, for instance, is disclosed in European patent application No. 1498734 A1. This document shows an automatic analyzer including a first storage case storing reagent containers for sample analysis, a supplemental second storage case storing reagent containers for supplemental use and a conveying unit for conveying reagent containers from the second storage case to the first storage case. While the first storage case is a rotatably driven reagent disk, the second storage case may have a box or circular shape and is rotatably driven to place reagent containers in a position facing a reagent container mounting opening used for transferring reagent containers from the first storage case to the second storage case. Hence, while the supplemental second storage case advantageously enables storing of an increased number of reagent containers kept in readiness for transfer to the first storage case for sample analysis, both storage cases require a lot of constructional space which, however, is not in line with the production of small and compact analyzers.